A relatively high percentage of U.S. population is overweight, that is, exhibiting a basic metabolic index or body mass index (BMI) greater than 25, and one quarter of the U.S. population is obese, exhibiting a BMI greater than 30. Annually, a large number of deaths can be attributed to obesity. Therefore, a healthy weight maintenance requires a balance between energy intake and energy output for an individual.
Adipose derived hormones such as adiponectin and leptin are secreted by adipose tissue and control various physiological systems in a mammalian body. Low leptin levels, for example, stimulate food intake, reduce energy expenditure, and modulate neuroendocrine and immune functions to conserve energy stores. While normally leptin is a signal that reduces appetite, it is known that obese persons have an unusually high circulating concentration of leptin and may be resistant to the usual effects of leptin in a manner similar to patients suffering from Type 2 diabetes that are resistant to the effects of insulin. High sustained concentrations of leptin may result in undesirable leptin desensitization or leptin resistance.
Adiponectin is produced by adipocytes in adipose tissue and is secreted into the bloodstream. Levels of adiponectin in the bloodstream are inversely correlated with body fat percentage in adults. It is believed that adiponectin plays a role in the suppression of metabolic events that may result in Type 2 diabetes and obesity.